1. Field of the Invention
This invention relates to transdermal medication assemblies and more particularly to such assemblies comprising multiple unit-dose reservoirs with each reservoir having individual tear-and-release or pull-and-release resealable closure means for initiation and administration of the medication.
2. Description of the Related Art
Transdermal drug administration has recently come to the forefront as a useful route for continuous dosing of useful drugs where other means of administration are either discontinuous, labor intensive or where other routes present absorption or inactivation problems. Whereas per os administration has been time honored i.e. "a teaspoonful three times a day", such unit dose administration was subject to erratic blood levels of the actives due to non-uniform absorption from the gut due to other gut contents or inactivation of the drug actives by the digestion process or the normal action of the liver. In addition, the need for active periodic administration i.e. three times a day, required active and willing participation by the patient or in home or hospital settings by the caregiver i.e. mother or nurse.
All these shortcomings are obviated by transdermal application where possible, of the drugs. A patch is adhered to a clear area of the skin and the drug is continually absorbed through the skin into the bloodstream for systemic distribution.
The skin is particularly useful as it presents large areas for drug administration, as the skin is the largest organ of the body. The utility of such a mode of administration has been promoted with the discovery and development of a group of compounds that promote transdermal penetration of the various active drugs. Such compounds are known in the art as penetration enhancers. They are generally characterized to be from the group of monovalent branched or unbranched aliphatic, cycloaliphatic or aromatic alcohols of 4-12 carbon atoms; cycloaliphatic or aromatic aldehydes or ketones of 4-10 carbon atoms, cycloalkanoyl amides of C 10-20 carbons, aliphatic, cycloaliphatic and aromatic esters, N, N-di-lower alkylsulfoxides, unsaturated oils, terpenes and glycol silicates.
These compounds and their specific activity as penetration enhancers, are more fully discussed in the text "Transdermal Delivery of Drugs, A. F. Kydonie US (Dd)-1987 CRL Press and in such as U.S. Pat. Nos. 4,913,905, 4,917,676 and 5,032,403.
As a result of these penetration enhancers, almost any drug, to some degree, can be administrated transdermally cf. U.S. Pat. Nos. 4,917,676, 3,598,122; 3,598,123; 3,742,951; 3,797,494; 3,948,254; 3,996,734; 4,284,444; and 4,597,961. Examples of such pharmacological actives include administration of antibacterial such as the penicillins, tetracyclines, second and third generation cephalosporins, chlor-amphenicol sulfonamides; sedatives and/or hypnotics, such as barbiturates, carbromal, antijussives such as codeine and dextromethorphan; anti-anxiety drugs such as the benzodiazepines including diazepam, buspirone; psychostimulants such as imipramine amitriptyline and other tricyclic anti-depressants; anti psychotic drugs and tranquilizers such as lithium, chlorpromazine and haloperidol, reserpine, thiopro-pazate; Parkinsonism control agents such as bromotriptine, percolide, the anticholmergics including benzotropine, pro-cyclidine, amantadine (also an antiviral); hormones and hormone antagonists and agonists, including adrenocortico-steroids; insulin, androgenic steroids, estrogenic and pro-gestrogenic steroids, thyroxin and its agonist 5-FU(fluoro-uracil), tamoxifen; antipvretics and analgesics such as aspirin/acetaminophen and other non-steroidal anti-inflammatory drugs (NSAID), analgesics based on morphine; morphine antagonists; vasodilating agents such as nitro-glycerine, isorbide dinitrate; alpha beta-blockers and other cardioactive drugs; antimalarials; anti-histamines and anti-cholinergics including atropine hyoscyamine or methscopalo-mine (for motion sickness; weaning agents such as nicotine for addiction to tobacco; and antiasthmatic bronchodilators such as formoterol; and combinations of such pharmaceutical actives.
Of course, while feasible, not all of these actives have yet been completely tested for efficacy by transdermal administration but many are under vigorous scrutiny. Other actives at this time are not economically viable for such administration, as the cost of full safety testing is too great for the specific number of patients involved.
As can be seen from this background discussion and the history of this type of medication, it is apparent that application by transdermal patch is a useful form for the administration of medication. However, a single dose per patch requires uneconomical repeated application.